Novel carboxylic acids and process for synthesizing carboxylic acids

ABSTRACT

A process for preparing novel carboxylic acids which process comprising heating aromatic compounds which do not readily undergo electrophylic substitution with 3-carboxyphenyl sulfonyl chloride at a temperature of about 150* to 350* C. for a period of about 0.25 to 24 hours in the mole ratio of 4:1 to 20:1.

United States Patent Fields [22] Filed:

[54] NOVEL CARBOXYLIC ACIDS AND PROCESS FOR SYNTHESIZING CARBOXYLIC ACIDS [72] Inventor: Ellis K. Fields, Chicago, 111.

[73] Assignee: Standard Oil Company, Chicago,

April 14, 1969 [21 I Appl. No.: 862,093

Related US. Application Data [62] Division of Ser. No. 542,208, April 13, 1966,

Pat. No. 3,442,939.

52 us. c1. ..260/515 A, 260/517, 260/396 R, 260/465 1), 260/511, 252/558 51 Int. Cl ..C07c 63/00 [58] Field of Search ..260/511, 517, 515 A, 396 R, 260/465 1) [56] References Cited UNITED STATES PATENTS 3,316,295 4/1967 Stames, Jr. ..260/515 A 1451 Sept. 5, 1972 OTHER PUBLICATIONS Fields, Chem. Abstracts 64, 633d (1965).

Snyder et al., J. Am. Chem. Soc. 71., 289- 291 (1947). Gilman et al., J. Am. Chem. Soc. 78, 2217- 2222 (1956).

Shriner et a1,, .1. Am. Chem. Soc. 79, 227 230 (1957). v I

Primary ExaminerDanie1 D. Horwitz Attorney-Pike H. Sullivan, Arthur G. Gilkes and Edwin C. Lehner [5 7 ABSTRACT 2 Claims, No Drawings NOVEL CARBOXYLIC ACIDS AND PROCESS FOR SYNTHESIZING CARBOXYLIC ACIDS This is a divisional application of Ser. No. 542,208 filed Apr. 13, 1966 matured into US. Pat. No.

This invention relates to the preparation of novel aromatic sulfonic and carboxylic acids. More particularly, it relates to the preparation of aromatic sulfonic and carboxylic acids from aromatic compounds by heating these aromatic compounds at elevated temperatures with 3-carboxyphenylsulfonyl chloride, and their utilization as surface active agents and plasticizers.

The method of this invention comprises heating aromatic compounds with 3-carboxyphenylsulfonyl chloride at temperatures of about 150 to 350 C., preferably 220 to 300 C., for 0.25 to 24 hours, preferably 0.5 to 18 hours, in the mole ratio of 2:l to 50:1, preferably 4:1 to 20:1, at pressures of l-100 atmospheres. Aromatic compounds that readily undergo electrophilic substitution give sulfonic acids, easily isolated as their potassium salts. These include diphenyl,

naphthalene, terphenyl, anthracene, phenanthrene, pyrene, chrysene, rubrene, and such aromatic rings containing one to five alkyl substituents, each with one to 40 carbon atoms, such as toluene, xylene, pseudocumene, durene, prehnitene, ethylbenzene, isoamylbenzene, dimethyl naphthalene, triisopropyphenanthrene, n-dodecyl naphthalene, and the like. Aromatic compounds that do not readily undergo electrophilic substitution give carboxylic acids. These include acetophenone, benzophenone, pdibromobenzene, trichlorobenzene, phenyl naphthyl ketone, anthraquinone, phenanthraquinone, diacetyl benzene, tetrafloro naphthalene, benzoyl pyrene, naphthoyl chrysene, benzonitrile, terephthalonitrile, naphthonitrile, and the like.

The preparation of sulfonic acids when aromatic compounds, which readily undergo electrophilic substitution, are treated with 3-carboxyphenylsulfonyl chloride is a novel reaction. This type of reaction is wholly unexpected, since if the Friedel-Crafts type of reaction were to be predicted, the products should have been sulfones instead of ketones. The sulfonic acids are also not produced by a rapid intraor intermolecular reaction of the carboxyphenylsulfonyl chloride to give sulfobenzoyl chloride. It was found that when 3-carboxyphenylsulfonyl chloride was heated at l93C.-that is 60 over its melting point-and then cooled, its melting point and mixed melting point were unchanged. Thus, according to the process of my invention, aromatic compounds that readily undergo electrophilic substitution give sulfonic acids when treated with 3-carboxyphenylsulfonyl chloride at elevated temperatures wherein the mole ratio of the 3- carboxyphenylsulfonyl chloride to the aromatic compound treated to greater than 1:1. The mechanism for the production of the sulfonic acids is apparently a thermal acylation.

The aromatic sulfonic acids are produced according to the following reaction:

with KOH 50 K I SOzUl This is an unexpected reacted reaction, since according to Friedel-Crafts the type of reaction should give the following products:

+ Arll O This confirms the novelty of my new synthetic method.

In accordance with my new method, the following new aromatic sulfonic acids were produced from diphenyl and naphthalene:

3-Sulfophenyl diphenyl ketone having the formula:

3-Sulfophenyl naphthyl ketone having the formula:

3-Carboxy-2,5-dibromodiphenyl having the formu- COQH and

This method is useful for producing other carboxylic acids such as 3-carboxyphenyl acetophenone, 3-carboxyphenyl dinaphthyl ketone, 3-carboxyphenyl anthraquinone, 3-carboxyphenyl phenanthrequinone, diacetyl 3-carboxydiphenyl, carboxy cyano biphenyl, carboxy dicyano biphenyl, and 3-carboxyphenyl naphthonitrile.

The products from the novel process of my invention are useful as surface active agents and plasticizers.

EXAMPLE I 3-carboxyphenylsulfonyl chloride was prepared by heating 360 ml. (5.5 moles) chlorosulfonic acid and 127 g. (1.04 moles) benzoic acid at 125C. for 1 hour, then pouring on crushed ice. The white solid was collected on a filter, washed with cold water, and dissolved in 300 ml. of benzene plus 50 ml. of heptane at 70C. The solution was decanted from the water layer, treated with 100 ml. of heptane, and cooledto 10C. The crystals were collected on a filter and sucked dry, giving 177.1' g. of 3-carboxyphenylsulfonyl chloride melting at l32+133C. The yield was 77 percent.

A mixture of 4.41 g. (0.02 mole) 3-carboxyphenylsulfonyl chloride and 46.2 g. (0.3 mole) diphenyl was refluxed for 5% hours, during which time hydrogen chloride evolved. The mixture was cooled to 85C., then refluxed for 1 hour with 200 ml. of benzene and 50 ml. of percent aqueous potassium hydroxide. The hot aqueous solution was cooled to C. and the white crystals which deposited were recrystallized from water, giving 2.7 g. (36 percent) of the potassium salt of 3-sulfophenyl diphenyl ketone/melting at 324-333 C.

Anal. for C H SO K:

Calculated: C, 60.6; H,.3.5; S, 8.5; K, 10.4

Found: C, 60.4; H, 3.7; S, 8.2; K, 10.8

EXAMPLE II A mixture of 6.62 g. (0.03 mole) 3-carboxyphenylsulfonyl chloride and 57.7 g. (0.45 mole) naphthalene EXAMPLE III For comparison, the acid chloride of 3-carboxyphenylsulfonyl chloride was prepared by warming a mixture of 22 g. (0.1 mole) of 3-carboxyphenylsulfonyl chloride and 20.8 g. (0.1 mole) of phosphorus pentachloride at 60C. till evolution of hydrogen chloride stopped, then stripping off the phosphorus oxychloride in vacuo. The residue was used with no further purification.

A mixture of 4.7 g. (0.02 mole) 3-chlorocarbonylphenylsulfonyl chloride and 46.2 g. (0.3 mole) diphenyl was refluxed for 4.75 hours, then worked up as in Example 1, giving 4.55 g. (60 percent) of potassium salt of 3-sulfophenyl diphenyl ketone, melting at 339342C.

Anal. for C H SO K:

Calculated: C, 60.6; H, 3.5; S, 8.5; K, 10.4

Found: C, 61.0; H, 3.6; S, 8.4; K, 10.

Its infrared spectrum (Nujol mull) was indistinguishable from that of the product of Example I.

EXAMPLE IV From a mixture of 4.78 g. (0.02 mole) 3-chlorocarbonylphenylsulfonyl chloride and 38.5 g. (0.3 mole) naphthalene, refluxed 18 hours, was obtained 4 g. (57 percent) of potassium salt of 3-sulfophenyl naphthyl ketone, melting at 285-292C.

Anal. for C11H11SO4K:

Calculated: C, 58.2;1-1, 3.1; S, 9.1; K, 11.1

Found: C, 58.0; H, 3.4; S, 8.8; K, 11.4 Its infrared spectrum (Nujol mull) was indistinguishable from that of the product of Example 11.

EXAMPLE V centrating, treating the hot solution with water till clou-' dy, and chilling. The crystals, phenyl carboxydiphenyl ketone, melted at 188192C.

Anal. fOr C20H|403I Calculated: C, 79.4; H, 4.6; neutral equivalent, 302

Found: C, 79.1; H, 4.8; neutral equivalent, 297

The acid was converted to its methyl ester through the acid chloride; the viscous ester boiled at 220C. at 3 mm. Its mass spectrum showed that the molecular weight was 316; theoretical molecular weight, 3 l6.

EXAMPLE VI A mixture of 4.42 g. (0.02 mole) 3-carboxyphenylsulfonyl chloride and 70.8 g. (0.3 mole) of pdibromobenzene was refluxed for 168 hours. One-hundred ml. of benzene and 50 ml. of 10 percent aqueous potassium hydroxide were added, the mixture refluxed 0.5 hour, and the aqueous solution was separated and acidified, giving 1.4 g. (19 percent) of precipitate.

The identical reaction was run with the addition of 0.2 g. cuprous chloride. The same workup gave 1.5 g. (20 percent) of precipitate, that was easier to crystallize than that above, from heptane. The crystals, 3-carboxy-2',5 '-dibromodiphenyl, melted at 2 1 3-214C.

Anal. for C 3H1 o2B1'2:

Calculated: C, 43.3; H, 2.3; Br, 44.9; acid number, 15 1 Found: C, 43.2; H, 2.5; Br, 44.6; acid number, 152

The prolonged reaction time and relatively low yield was because of the low boiling point of pdibromobenzene. Best results are obtained at 240C. or above. Pressure vessels may be used especially if provided with a means of venting the sulfur dioxide and hydrogen chloride formed in the reactions.

1 claim:

1. A process for synthesizing aromatic carboxylic acids, which process comprises heating aromatic compounds selected from the group consisting of acetophenone, benzophenone, p-dibromobenzene, trichlorobenzene, phenyl naphthyl ketone, anthraquinone, phenanthraquinone, diacetyl benzene, tetrafluoro naphthalene, benzoyl pyrene, naphthoyl chrysene, benzonitrile, terephthalonitrile and naphthonitrile with 3-carboxypheny1suifonyl chloride at a temperature of about 150 to 350C. for a period of about 0.25 to 24 hours in the mole ratio of 4:1 to 20: 1.

2. As a composition of matter 3-carboxy-2,5'- dibromo-diphenyl. 5 

2. As a composition of matter 3-carboxy-2'',5-dibromo-diphenyl. 